Boston Computer Society - Sinclair Timex User Group Newsletter

GOGO The Boston Computer Society

SINCLAIR-TIMEX USER GROUP NEWSLETTER

Volume 2, Issue 6 June 1983

This newsletter ts produced to inform group members of the agenda and
logistics for future meetings, as well as to recap and amplify the information
provided at the last meeting. It also provides a forum for members and
interested parties to communicate what they have learned or developed relating
to Sinclair and Timex computer products. Meetings are open to the public;
however, attendees are encouraged to join the Boston Computer Society (BCS).
This newsletter is free to members. Back issues are one dollar each.

USER GROUP MEETING

Date: Wednesday, June 15, 1983
Time: 7:00 pom.
Place: Large Science Auditorium

UMass, Harbor Campus
(Directions on Last page)

At the June meeting, Dave Miller will demonstrate and explain QSAVE and
FASTLOAD--programs which are available from Gladstone. In addition, Bill
Russell, whe runs a user group in central Pennsylvania, and edits the Synapse
newsletter, will speak. The topic is his "Winky Board" and other new
products, including a method for creating high resolution 3-D pictures on the
Timex printer. Bill will have Winky Boards, a device to help loading and
saving programs from tape, available to members at the meeting at a discount.
They normally retail for $24 assembled and $18 for the kit.

We will break into groups to discuss topics of interest. Tentatively, an
advanced and a beginner’s group are planned.

If you have items to discuss at a future meeting or suggestions for
presentations, contact Sue or Cliff.

HERALDING THE MACHINE LANGUAGE SUBGROUP

Robert Heath has volunteered to organize a machine language special
interest subgroup. At the regular meetings, we strive to balance
presentations to cover many areas and levels of expertise. The subgroup
provides an opportunity to focus on machine language. In addition, it gives
enthusiasts a chance to meet more Frequently than once a month. ‘The first
meeting is tentatively planned for July 6th at ITEK Optical Systems in
lexington. For details contact Robert during the day at (617) 276-2424.

HIGHLIGHTS OF THE MAY MEETING

Sue Mahoney surprised us this month by bringing a prototype of the
long-rumored but just announced TS-1500. The 9 1/8 by 5 3/8 by 1 3/4 inch
silver box is an improved version of the TS-1000. It has moveable keys, 16 K
of RAM, better filtering to make tape loading and saving more reliable, and
some ROM improvements (see page 10). You will also be able to plug your 16 K
RAM pack into it to get 32 K. Sue said the TS-1500 will List for $79.95 and
will be shipped to distributors in July. The TS-1000 will continue to be sold
at its lower price. The most marked improvement we saw was in the TS-1500
keyboard, which employs the same conductive rubber technology as the Sinclair
Spectrum, but doesn’t have the Spectrum keyboard’s “squashy" feel. In
addition, none of the screws holding the box together are under the footpads.

John Kemeny described the Timex/Sinclair User Magazine group discount,
which some people did take advantage of--sorry, its expired by now. He also
passed on a request from Brady Publishing for volunteers to review manuscripts
and proposals for computer related books. There is a small honorarium. Many
people volunteered. John also stressed the need for volunteers to do user

group work. (New members are particularly encouraged to get involved. Job
descriptions are available if you’re interested.)

Beth Elliott described the latest additions to the library. She said the
original library fund (which was a donation from Maggie Bruzelius of Sinclair
Research) is pretty much exhausted. Beth is looking for volunteers to solicit
publisher contributions. She noted that Reston has already been very generous
with us. Beth, who works at Sinclair Research, also announced that Sinclair
has available, for bulk purchase, power supplies and transfer switches (those
television antenna game boxes).

Jack Hodgson, our publisher, briefly discussed the evolving advertising
policy: (1) to accept ads only for computer-related products and services,
(2) to devote at most 25 percent of the newsletter to ads, and (3) to limit
ads to 1/4 page to give more advertisers a chance. Jack is also interested in
the group putting together a scrapbook of clippings about the Sinelair-Timex
and related products. Send your contributions to Jack.

Dan Roy, our main speaker, presented a prototype of the COLORSIN81, a
color add-on he designed. COLORSIN81 is a peripheral to the TS-1000 which
gives it functions similar to the Spectrum. Due to the unavailability of the
proper RF modulator, Dan was unable to demonstrate the 15 colors, 32 sprites,
and high resolution aspects of his system. We did hear the three independent
sound generators, each of which has a range of ten octaves. ‘They were loud
enough so that some of us are still hearing them! A 2 K PROM, which maps into
the 12 to 14 K address space, implements 17 new Basic commands, such as
SOUNDON. The system also supports two potentiometer type joysticks and a
six-slot motherboard for expansion. An article on Dan‘’s system, complete with
schematics and construction tips, will appear in the July/August issue of Sync
magazine. Currently, Dan is negotiating with a manufacturer to bring out a
product. The price of a kit would be about $160. Dan has offered to host a
kit building session, if there is interest.

Dan also demonstrated the CAI/Exatron stringy Floppy, a continuous leop
tape system which allows for rapid saving and loading of programs. At 11000
baud, it can save a 16 K program in less than 25 seconds. The special
"skinny" tape comes in a cartridge about 1 inch by 2 inches, and can store
eight programs. A 2 K PROM mapped in the 10 to 12 K region interacts with the
user through a menu. The menu options are: Save, Load, Certify (i.e,
initialize the tape), Basic, and Drive (two drives may be connected

HIGHLIGHTS -- Continued

simultaneously). Dan says a useful feature is the ability to “chain”
Programs. That is, one program can call another (on tape) without user
intervention. Dan likes his Exatron and considers it his most valuable
peripheral. The only drawback he has found is the system’s inability to copy
software which is self-running (the menu which comes up after a load prevents
self-running programs). The Exatron costs $119.95 and may be ordered from CAL
Instruments in Sanford, Michigan.

There was also some discussion about the incompatibility between
Memotech’s Memopak memories and the new Timex printer. Memotech acknowledges

that some of their 32 K and 64 K memories are incompatible, but they don’t yet
know what the problem is.

WHY USE MACHINE CODE? by Dave Wood

Reason number 1 (with apologies to H&R Block): speed. The BASIC on the
Sinclair-Timex computer is an interpreted language and, therefore, relatively
slow when compared to the execution speed attainable by using the underlying
processor. To do a simple comparison, try the programs in figures 1 and 2.
Run them in SLOW mode to observe the difference.

LD OA, 17h
200 PRINT "*"; 10 REM Y*NOT /CLEAR LOOP RST 10h
210 GOTO 200 20 RAND USR 16514 JR LOOP
Figure 1 Figure 2 Figure 3

Figure 3 is the machine language program stored in the REM in line 10 of
figure 2. To enter the REM statement, type in: 10 REM Y*NOT / THEN CLEAR
then use the backspace cursor (shift-5) and DELETE key (shift-0) to delete the
THEN token. Make sure you enter the tokens NOT and CLEAR.

A QUICK WAY TO DISPATCH THE EDIT LINE

Did you ever notice that in department stores which showcase the TS-1000,
the edit line is always filled with umpteen lines of garbage? You don’t have
to do scores of DELETEs to get rid of it. Just press EDIT (shift-1) followed
by ENTER.

RANDOM POKES

The RAND command sets the 2-byte system variable SEED, which is located
at addresses 16434 and 16435. The variable is set to the expression following
RAND (except RAND O--what happens then?). Unlike functions, the expression
does not require enclosing parentheses. We tell you this because to do USR
calls many people use: RAND USR address. If you don’t want the "side-effect"
of changing the random number seed in USR calls, try: IF USR address THEN.

Tf you are not using the random number seed, there is a simple way to
convert a floating-point number N into a 2~byte integer. Replace the two
statements, POKE 16435, N/256 and POKE 16434, N-256*INT (N/256), by RAND N.

AN

ROM BUG #3 REVISITED

Last month’s ROM Bug #3, which causes numbers with leading zeros (i.e.,
0.01 thru 0.00001) to be LPRINTed incorrectly, was independently discovered by
Robert L. Carter. He sent Timex the program in figure 1 to illustrate the
problem. To make the program do what it should, add line 25 LET A$=STR$ A
and replace the variable A in line 40 with A$. Timex replied that they were
able to correct the ROM code for the next generation of Timex computers.

In the meantime, Mike Wagner of Wankesha Wisconsin sent a letter to
Syntax (Volume 4, Number 5; May 1983) describing the problem in the ROM. The
routine to output leading zeros of a floating point number with negative
exponent is shown in figure 2. Mike’s solution is to change the destination
of the DJNZ from LOOP to ALT, i.e., change ROM address 016BC from FD to FB hex.
RST 10 outputs the character in the A register to either the screen or the
printer. The problem is that the LPRINT routine at 0851 hex forgets to
testore the A register before returning. So what is in the A register is the
low byte of the address of the current position of the print buffer (anything
from 3C to 5C hex). Adding the required LD C,A instruction to LPRINT would
mean moving every byte in the ROM that follows the change. This would change
ROM routine entry addresses, not required by Mike’s suggestion. It will be
interesting to see how Timex has solved the problem.

10 INPUT B

15 INPUT t

20 CLs

30 LPRINT

40 LPRINT TAB 1,B;

50 FOR I=16442 To 16444+32
ALT LD A, lth 60 PRINT I;" “;PEEK I,
40 LPRINT TAB I;A LOOP RST 10 70 NEXT I
50 NEXT I DJNZ LOOP 80 GoTo 10
Figure 1 Figure 2 Figure 3

in case you don’t have a Timex printer, the program in figure 3 can be
used to verify the bug. Input a number between 0.01 and 0.00001 and a number
for TAB spacing. The screen shows the bytes stored in the print buffer
awaiting printing. The semicolon in line 40 is important because it keeps the
result in the print buffer. Without the semicolon, the result would be sent
to the printer and the buffer cleared. The numbers you will see represent the
bytes For the decimal point (27), the first zero (28), the bytes in error, and
the rest of the number (29 for a one, for example).

ROM BUG #4

In the May issue of Syntax, Dean A. Cuadra, of Los Angeles California,
reported that it is possible to crash the system without using POKEs with the
program:

10 GOSUB 20
20 GOTO 10

Executing GOSUB pushes a return "address" (actually a line number) onto
the computer’s stack. To remove this entry requires the execution of a RETURN
command. Obviously, executing too many GOSUBs without RETURNe will use up all
the memory~-the computer stops with error report 4. Se where’s the bug? The

bug is that there is no effective way to clear the stack without executing a
NEW or pulling the plug. Using RETURN doesn’t work because once you execute
it you lose control--the computer gets the address of the next line from the
stack. The logical command to clear the stack is CLEAR, but it doesn’t.
CLEAR just deletes the variables. Just for fun, lets see out how many times
we can push the GOSUB stack. Figure 1 shows a straightforward attempt. Since
the program stops on an out of memory error, we won’t have any room in the
display file to PRINT A, the answer. Therefore we put in line 1O to take up
space. After the program stops, we can delete line 10, PRINT A, and voila!
Well, not quite voila. You see, when the stack overflows, it overflows into
the variables area, corrupting the value of A. We'll have to put the result
someplace other than a variable. Figure 2 is a program which puts the result
in the random number seed--an application of the hint on page 3. Also,
instead of the REM statement taking up space, we used a dummy variable AS.
After RUNning the program, use CLEAR to buy back space. Then type GOTO 70 to
print the result. The answer depends on how much memory you have. Although
in general we can’t use RETURN to clear the stack, in this case we can.
Change line 30 from GOSUB 50 to RETURN. Now RUN the program again. It should
stop with error report 7. Type a GOTO 70. What do you find?

10 REM OVERFLOW THE STACK 10 DIM A$(50)
20 LET A=1 20 RAND L
30 GOSUB 50 30 GOSUB 50
50 LET A=A+1 50 RAND 1+PEEK 16434+256*PEEK 16435
60 GOTO 30 60 GOTO 30
70 PRINT PEEK 16434+256*PEEK 16435
Figure 1 Figure 2
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ORGANIZER APPLICATION by Jack Hodgson

My roommate,Mark collects “Top 40" singles. He owns over 3500 45 rpm
records. Some were hits as long ago as the 1930s, but most are from the last
20 years. In addition to maintaining this collection for his own enjoyment,
he uses it to earn money as a dance deejay. He, his sound system, and his
3500 plus records go to dances, parties, and other assorted functions.

Over the years, Mark has created a file of his collection using 4 by 6
inch index cards (figure 1). These cards contain, in addition to the title of
the record and the artist’s name, information about when the record was
released, when it entered the top 100, when it dropped from the top 100, the
highest position it reached, and cross references of performers who were with
other groups. Mark keeps this file in alphabetical order by artist’s name.
The file occupies two and one-half l5-inch file drawers.

A few months ago Mark created a data base of his collection using the
Organizer program from Timex. Although it would be valuable to be ‘able to
update and print out the file more easily, his main goal was to be able to
search through the date and top 100 position information. Often, when he was
playing records at a party, guests would make a request like this: "We
graduated school in 1972, can you play some songs that were hits that year."
In the past, he dealt with these requests from his own knowledge of music.
and although his knowledge is amazingly comprehensive, it 1s not totally
complete.

In creating the file, Mark realized right away that it was going to be
difficult, if not impossible, to code 3500 records into 10,000 bytes of
storage space (DIM F$(9999)). He dealt with this problem in the time honored
fashion of deciding to think about it later. In the meantime, he resigned
himself to storing the information in more than one tape cassette file.

The next question was how to format the file. He set up the screen
rather straightforwardly (figure 2}. The first field contains the artist’s
name, the second is a cross reference, when needed, to other groups.
Subsequent fields alternate between one with a song title and one containing
the year and position information. On his index cards, information is simply
aumbers separated by markers. He knew from memory which column contained
which piece of information. To make data base searches possible, he added
letter postseripts to the numbers. Without the letter, a search on 65 could
be interpreted as “entered chart at number 65," when it really meant "released
in 1965." In this data base, 65N means the former and 65Y the latter.

As it stands, the program does the job expected of it. It can search for
and find entries by song title, top position, year released, etc. It can
reorder the file by any Field and it can easily be updated. The main problem
now is that, in order to do a complete search, the program must be loaded
several times. Each load contains part of the data base. Mark is currently
looking for ways around this problem.

Here are a few of the solutions under consideration. Reduce the artist’s
hane entry to one or two bytes, which can be looked up in an external index.
Encode common words such as “love,” "you," "him," and "her" a single byte
which is decoded and printed correctly on the display. Mark is also looking
into the data compression techniques reported in previous issues of this
newsletter. The last two solutions will, of course, require changes to the
Organizer program. But then it’s not written in stone. (Boy! If it were
would it be slow then!)

ORGANIZER APPLICATION -- Continued

Perhaps the ultimate solution to these problems is to add hardware. A
64 K RAM pack, a stringy floppy, or a full fledged disk drive would do the job
easily. But I’d like to think that the first way to solve any problem is
through efficient programming.

So there’s Mark’s Organizer application. It’s not perfect but it beats
the hell out of those index cards. I’d love to hear from anyone who has any
ideas about this application.

= s ENTER ALTER INFORM
PeenARD BACH RESET ORER SELECT
SUIT LIST PRINT COPY DELETE
=
AHEKA cee : TAY

= Released in 1974
45 WING My BABY 30N = Entered Chart Number 30
NGAP 2 40F 725 oneal Me 01P = Top Position Number 1
45 ONE MAN WOMAN/ONE UOMAN MAK a f Year
Fay ABN OTP SBF 728 7 40F = Left Chart 40th Week o
45 LIKE TO SLEEP ALONE 25 = On Chart 25 Weeks
13H /@8P -23F 722
45 TIMES oF
FEY /45N/Q07R “SOF 1283
45 (I BELIEVE) THERES NOTHING

STRONGER THAN CUR LOVE
PSY -2BN/ LSP dQ 415

45 ITS TIME To cry
RAEX

figure 2

ANKA, Paul — |

45 (fou' RE) HAVING MY BABY / papa
MAAT YQ BABI; SIFY; ICT TY PRO N0-aS exe S

45 ONE MAN WOMAN / ONE WOMAN MAN “ let me get to know

F4-4O- 09-56-28 Bot & you
45 I DON'T LIKE TO SLEEP ALONE / how can anything be
FS 713 -09-23-da Deo E beautiful-efter you

“45 IT'S ‘TIME TO CRY / something has changed me

MS i bay thal ter runs deep
“45 7 ING STRONGER THAN OJ.
ay I vecane a fool
45-33- eat ics

R LOVE/

figure 1

KNOWING LEFT FROM RIGHT

What is the order of evaluation for expressions in the Sinclair-Timex?
This question, which came up at the last meeting, is not as complex as it
sounds, 4+(2*3) is 10, and (4+2)*3 is 18, obviously. But what is 4+2*3? The
answer is 18. This is because there is a precedence between the operations +
and * which gives priority to *. That is, if there are no parentheses,
multiplication is done before addition. What about 5*3/2? According to the
manual, expressions involving operators which have the same priority, like *
and /, are evaluated left to right. That is, as if the expression were
(5*3)/2. We can see this by examining the part of the ROM called the parser.
The problem is, can we convince ourselves of left to right evaluation by
looking at results of BASIC expressions?

PRINTing (5*3)/2 and 5*(3/2) won‘t tell us anything, since both results
are 7.5. When an operation, call it @, is such that (a@b)@c is equal to
a@(b@c), the operation is called associative. In our computer, operations
with the same priority are associative with respect to the floating-point
numbers used by the computer. But all is not lost. Allan Cohen, at the last
meeting, came up with an ingenious solution using error messages. First,

LET X=2**126, close to the largest number that can be represented as a
floating point number. Now, look at the expression 2’x/2. A left to right
evaluation, (2*X)/2, would yield an overflow error, while 2*(X/2) would print
a valid number. What happens when you PRINT 2*X/2? As a variation on this
theme, try PRINT 2/0*4G, where 2 is divided by zero and G is undefined. The
expression (2/0)*G will halt with error 6 for division by zero, while 2/(0*G)
will halt with error 2 fot undefined variable. Is there a way to distinguish

left from right without using error messages?

IS GLARE GETTING YOU?

If you didn’t attend the February
meeting, you may have missed this
suggestion from Will Stackman. To
reduce eye strain when using the
computer, OSHA recommends the use of a
yellow or amber monitor. In Europe,
such monitors are very popular;
however, due to their cost, they are
not too popular in the United States.
To convert a black and white monitor
or television to an inexpensive yellow
monitor, cover the screen with a sheet
of theatrical color medium (gel), such
as Roscolene. This can be purchased
from a theater supply store. A 22 by
28 inch sheet costs about $3. Will
says he prefers a light amber color.
It can be taped to the set and removed
for cleaning with a soft dust cloth.
You could even use an anti-static
spray for cleaning the dust from the
film.

Send us your comments.

The Boston Computer Society helps make sense
out of personal computers. If you're interested in
computers for home, business or education, come to
The BCS for objective information and support. The
BCS is the largest nonprofit personal computer asso-
ciation in the United States; our goal is not topro-
mote any particular brand of computer, but to help
computer users and people who just want to know
what a computer could do for them.
Sign me up for these user /interest groups:
OU Apple/Boston (Apple)
Atari User Group
O Business User Group
OD Consultants & Enttepreneurs Interest Group
0 Database User Group
O Displaywriter User Group
O Educational Resource Exchange
© 80/Boston (TRS-80)
O Family Home User Group
D Logo User Group
O IBM User Group
D North Star User Group
O Osborne User Group
OSI/Boston (Ohio Scientific)
C Pascal User Group
O PET/CBM/VIC User Group
© Robotics Interest Group
¥ Sinclair/Timex User Group
D ‘Telecommunications User Group

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UPDATE ON THE LIBRARY by Beth Elliott

The latest library additions are Learning Timex Sinclair BASIC by David

A. Lien, The Timex Personal Computer Made Simple by Joe Campbell, and The Best
of Sync edited by Paul Grosjean. In addition, we have nine other books, 1!
programs, a user groups’ newsletter collection, a Syntax magazine collection
(nearly complete), and assorted advertisements From software and pecipheral

companies,

Our current policy toward borrowing copyrighted software is: (1) only
one tape per borrower, and (2) the borrower must agree to present the software
to the group and/or write an evaluation of the software for the newsletter.

UPDATE ON THE BCS BULLETIN BOARD

Ken Pugh has constructed and is maintaining a bulletin board for the BCS.
The bulletin board offers screens of information about the BCS and its user
groups. It also has advertising and the capability to leave Messages. Access
to the bulletin board is free and the size of the screens are compatible with
the display on our computer. Currently, the Sinclair-Timex User Group

maintains four screens of information.

These are to describe when and where

we meet, announce the activities for the next two meetings, and identify

additional sources of information.

Currently, Cliff Danielson is maintaining

these screens. Temporary screens are available, following the user group
screens, if you want to leave a message for other Sinclair-Timex users. A 300
baud modem is needed to access the bulletin board. The telephone number is
(617) 969-9660. Use an 8-bit code, no parity, and one stop bit.

THE TS-1500

As you could read in the highlights, the TS-1500 is an improved version

of the TS-1000 in TS-2000 packaging.

With a nice keyboard, 16 K of RAM, and

an $80 list price, they should be in the stores by August--but they won’t stay

there very long.

What do you do with your 16 K Ram pack?

Just plug it into

the TS5-1500 edge connector (all the connectors are on the back, by the way)

and run with 32 K.

In order to accomplish this nice little feat, we figured

Timex had to redesign the custom uncommitted logic array chip (ULA or mystery

chip, as we call it).
will have a 68-pin CMOS chip!

Indeed they did.

Instead of a 40-pin bipolar chip, it
CMOS technology greatly reduces the power

consumption, eliminating possible heating problems and allowing for far longer

operating time from batteries.

completely decoded to the bottom 8 K of memory.

A new chip also allowed the ROM to be

Timex also announced that the TS-1500 will also feature solid-state
cartridge software and 8-bit bank switching to give 64 megabytes of
addressability-~like the TS-2000 series (series?}.

chip when it becomes available?
select line for the ROM.

The ROM will also be different.
article in this issue);

numbers like 13.0 are equal to 12.999999999999;

The changes will:
modify the compare routines so that floating-point
add to the reboot routine at

Will it use the new Z800
The only change to the bus will bé the chip

fix ROM bug #3 (see

03CA hex for tuning to the proper TV channel (no more switch on the bottom).

-tag TS-1000 software base.

of these changes should the affect the TS-1500’s compatibility with the

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TimeWare Bookware

Explorer's Guide to the ZX-81 and
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Mike Lord

Mastering Machine Code on Your
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Toni Baker

50 1K/2K Games for the Timex.
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Alastair Gourlay et al

The Timex/Sinclair Pocket Book

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Making the Most of Your Timex
Tim Hartnell

49 Explosive Games for the Timex
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11480 Sunset Hills Road
Reston, VA 22080

or call our toll-free number:
800-336-0338
and ask for TimeWare Marketing

INCREASE THE POWER OF YOUR
TIMEX SINCLAIR 1000 with
INTERCOMPUTER PACKAGES

We offer up to 20% DISCOUNT for user
Groups and Students on our Peripherals and
Software in the areas of:

How will you take your
SYNTAX / Syntax Quarterly?

The Combination—12 issues SYNTAX, 4

: issues SQ $39
° Education ¢ Home Management The Catch-up—SYNTAX Jan, 82-Dec. 83,
* Entertainment * Programming Tools SQ Nov. 82-Nov. 83 (5 issues), 1 binder $77
© Utilities * Word Processing The Works—SYNTAX Nov. 80-Nov. 83,
AND SQ Nov, 82-Nov. 83 (5 issues), 2 binders $97
Memory Expansion — Printers. 12 issues of SYNTAX $29
RAMS ¢ Flexible Ribbon 4 issues of SQ, Syntax Quarterly $15
© Interface Connector lissue SQ O Winter O Spring O Summer $ 4.95

© OSAVE-Quick * High Resolution 1 Magazine binder to hold your SYNTAX or SQ. $ 9

Loading Graphics

AND MORE

NEW: Software on cartridges, Softbox,
and Intercontroller
To order or for more information and free
brochure, write or call Intercomputer, Inc.
PO. BOX 90, Prudential Center, Boston, MA
02199 Tel. (617) 437-1190

Coming soon: A tull line of Software and
Hardware for Timex 2000 and other

smal! computers.

ATT: Programmers. better royalties
for your high quatity programs

To order or request more info, call 617/456-3661. Or
write SYNTAX/SQ, RD 2 Box 457, Harvard, MA 01451.

SYNTAX / Syntax
Quarterly for Timex
Sinclair computer
users.

|

LISTING AND LLISTING WITHOUT LIST AND LLIST by Dave Wood

The following BASIC program was
developed to get BASIC listings on a
printer which cannot do LLIST, such as

the Okidata printer in the May 9973 LET Qe:
newsletter. The concept is to use the 9974 LET
display file as a buffer between the ee Te .
encoded BASIC in the RAM area following Oo77 IF pe
address 16509 and the characters needed 9978 PRINT 256)
9979 LET NI

to print out. The screen is cleared.
Then a program line is printed on the
screen, one character at a time, till a
line is complete. This line is then sent
to the printer, one character at a time.
The process stops when the next line
starts with the ENTER token (118).

Another application of this routine
is as a substitute for LIST. Replace
line 9987 with GOTO 9976, and simply omit
lines 9988 to 9999 and line 9973. It
works just Like LIST, but now when the
screen is full, instead of typing LIST
with a new line number, just enter
CONTinue. Try LISTing every other line,
or the line numbers used by your program.

9980 FOR K=1+4
9981 LET B=REEK 4
9982 If B26 THEN LE
9983 IF B=126 THEN GC
904 PRINT CHR By;
9985 NEXT X

2988 LET N-DEEK Ha
9989 FOR X=1 10 148
$999 LET DaREEK X

9992 DOME 16506, 0
9993 LET isugh A
9994 NEXT K

9995 POKE 16506, 13!
9996 LET Leuse A

FOR MORE INFORMATION

Sue Mahoney, Director of the Sinclair-Timex User Group
c/o The Boston Computer Society or call (203) 573-5816.

Jack Hodgson, Publisher
P.O. Box 526, Cambridge, MA 02238, (617) 354-7899

Cliff Danielson, Editor
14 Davis Road, Chelmsford, MA 01824, (617) 256-4638.

John Kemeny, Contributing Editor & User Group Correspondent
284 Great Road, Apt. D5, Acton, MA 01720.

Library Committee: Beth Elloitt, Sean O’Rahilly, and Bob Sanchez.

* ADVERTISING: INFORMATION :
Computer Related Products and Services Only

Open Rate: $40, per ‘Quarter Page
For Rate Card and Discount Informdtion Contact the Publisher

DIRECTIONS TO THE MEETING

The Sinclair-Timex User Group meets in the Large Science Auditorium (Room
8/2/009) of the University of Massachussets of Boston, Harbor Campus. The
Harbor Campus is only 3 miles from downtown Boston and easily accessible by
public and private transportation. From the north or west, take the Southeast
Expressway to Exit 17. Turn left onto Columbia Road. Enter the rotary and
take the firet right (Morrissey Boulevard). SBéar right on the traffic island,
following UMass/Boston sign. Turn left into the Campus. From the south, take
Morrissey Boulevard northward to the campus. On the MBTA, take the Red Line
(Ashmont Train) to Columbia Station. Transfer co the free University
shuttlebus in the T parking lot.

ind The Boston Nonprofit
d U.S. Posta
© Computer Society é Paid
ermit
Three Center Plaza Boston, MA

Boston, MA 02108
617-367-8080